This study is designed to determine how chronic adolescent cannabis abuse affects processes of impulsivity, attention, memory, and executive function, and to characterize how these processes are related relationship. This proposal is an exploratory grant (R21 funding mechanism) submitted in response to RFA DA-05-007, which focuses on the consequences of adolescent substance abuse. Adolescence is a critical developmental period when young people learn to regulate their emotions and behaviors, and learn skills to cope with increased environmental demands and autonomy. Maturational changes related to reward-seeking, motivation, and self-regulation occur during adolescence and this development extends into young adulthood. These developments occur across multiple domains of behavioral, cognitive, and neuro-physiological functioning, and cannabis has the potential to negatively affect any or all of these processes. Studies of adults and animals have demonstrated cannabis affects on these domains. Unfortunately, cannabis use most often begins during adolescence when individuals are at increased susceptibility to these disruptive effects on development. Antecedents and consequents of cannabis use on the developing behavioral, cognitive, and neurophysiological processes during adolescence have not been adequately tested and remain poorly understood. Advances in technology now allow for a more sophisticated understanding of the aspects of information processing and behavior impacted by cannabis abuse. The proposed study is unique because it brings together a group of established experts using a multidimensional approach to determine the impact of cannabis use on behavioral impulsivity and within the broader construct of information processing (including attention, memory, and executive function). The three primary aims are to determine: (1) the effects of chronic adolescent cannabis abuse on distinct components of impulsive behavior; (2) the effects of chronic adolescent cannabis abuse on attention, memory, and executive function; and (3) how each of the components of impulsivity are related to deficits in aspects of information processing (attention, memory, and executive function) among chronic cannabis abusers and controls. Relevance of Research to Public Health: This study will produce information that will advance our knowledge of the effects of chronic cannabis abuse during adolescence, with the potential to alter the methods and technologies that drive the field of substance abuse research. First, the study focuses on an adolescent sample, which is the age-range with a highest potential risk for lasting neurocognitive effects from cannabis use. Second, the study tests a model of impulsivity, which is central to many aspects of substance abuse. And third, data obtained with the multidimensional model of impulsivity will be interpreted within the context of broader information processing systems, which allows for a more sophisticated understanding of the behavioral effects occurring as the result of cannabis abuse during adolescence.